Nitrogen molecular area hydrophobic surfaces

It has been shown that nitrogen occupies a larger area on hydrophobic surfaces than on polar surfaces. The nitrogen molecular area on hydrophobic surfaces is estimated to be between 19 and 22 A [71]. 

Fig. 9.1-7 Example of principle component analysis comparison of synthetic drugs and natural products. A set of 20 synthetic drugs, including the top 10 best-sellers in 2004, and 20 natural products was analyzed for nine molecular descriptors molecular weight, hydrophobicity (X log P or C log P), hydrogen-bond donors, hydrogen-bond acceptors, rotatable bonds, topological polar surface area [43], stereogenic centers, nitrogen atoms, oxygen atoms. PCA was used to reduce the nine-dimensional vectors to two-dimensional vectors, which were then replotted as shown. The first principal component accounts for 55.1% of the original information and the first two...

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